In Scallet et al U.S. Pat. No. 3,305,395 there is disclosed and claimed a molecular exclusion and ion exclusion process resulting from the alkali isomerization of a high D.E. feed. The product of this invention, while quite useful and unique, contains a substantial percent of disaccharides and higher sugars. The present invention provides a process for obtaining a product even higher in fructose and lower in higher saccharides and higher sugars. Also, assigned to assignee of this invention are Katz U.S. Pat. Nos. 3,684,574 and 3,690,948 which disclose high fructose containing syrups made by resin isomerization processes. The products of these inventions are suitable as feed products for the present invention as are the products made according to the enzyme isomerization process of co-pending applications Ser. Nos. 218,476 and 296,000 of Shieh et al.
The state of the art of separation of fructose from glucose in conventional invert sugar, i.e., sugar made from sucrose solutions, is shown in Serbia U.S. Pat. Nos. 3,044,904 and Melaja 3,692,582. Both of these patents relate to invert feeds which means that the feed and also the final products contain sucrose. Also, the throughput of the processes of these patents is quite low compared to the throughput needed for an economical process using a corn conversion syrup.
An advantage of the improved process of this invention is its economic feasibility as well as the production of a product with a high fructose content, lower polysaccharide content and low dextrose content to permit a higher solids level in the finished product without crystallization of dextrose. The product of this invention is a syrup containing at least about 52% fructose (preferred at least 55% fructose) which can be concentrated to 80% or higher dry solids to yield a non-crystallizing syrup at a higher solids level and fructose level than present commercially available isomerized syrups.